No. 13/August 9, 2013
Now is the time to be scouting for white grubs throughout the state. The eggs have hatched so there are grubs to find, but they will be too small until mid to late August to eat enough roots to cause dieback.
Various caterpillars attack trees in late summer and early fall. These include fall webworm, yellownecked caterpillar, walnut caterpillar, sumac caterpillar, and whitemarked tussock moth. The damage caused by these caterpillars to attacked trees is relatively slight because the leaves have already produced most of the food for the tree that they will produce. The loss of leaves at this time of year is not very important to the tree. The main tree health concern about late-season defoliation is that the tree will break lateral buds and replace the lost leaves.
Got Spots on your Tomatoes?
This year, many bacterial diseases are being reported in tomatoes. First of all, when tomato foliage is infected with bacterial diseases, they can be easily misdiagnosed as other diseases. So, the first step is proper diagnosis, which can be obtained by submitting a sample to the U of I Plant Clinic. We are able to diagnose bacterial diseases on tomato in our lab by cutting lesions and placing them under a microscope.
Pachysandra Leaf and Stem Blight
When sited properly, Japanese pachysandra (Pachysandra terminalis) is considered to be a mostly trouble-free species. However, it occasionally will have problems with scales and a few fungal diseases.
Invasive Species Roundup
Emerald ash borer, Asian longhorned beetle, and thousand cankers disease are covered this week.
Modified Growing Degree Days (Base 50°F, March 1 through August 8)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the links below with the degree day accumulations above to determine what insect pests could be active in their area.